In an automobile industrial field, somewhat recent requirements have led to a vehicle inside space, which provide comfortable feeling to occupants. In order to meet these recent requirements, a recent vehicle is provided with various types of devices that help to achieve the comfortability. The vehicle door driving system is employed so as to automatically operate a vehicle door such as a power sliding door, a power back door and a power luggage door. A driving force of a driving power source such as a motor achieves an automatic opening and closing operation of the vehicle door in response to a simple and easy operation by a user, e.g., in response to a switch operation.
This type of vehicle door can be automatically opened and closed from a vehicle inside. Especially for children and elderly people, this type of vehicle door driving system offers gratification in opening and closing the vehicle door with less human power and easy operation. On the other hand, the automatic operation of the vehicle door may become disabled due to unanticipated occurrences such as a failure of the vehicle door driving system. When encountering this sort of unanticipated occurrence, the user tends to open or close the vehicle door manually. However, relatively large mechanical friction between the vehicle door and the driving power source may disable the vehicle door opening and closing operation. Further, the relatively large mechanical friction may makes the vehicle door opening and closing difficult.
From a different point of view, the vehicle door manual operation may be required for other reasons, which are different from the unanticipated occurrences such as the system failure. In light of foregoing, recent requirements have further lead to a vehicle door operation system, which can switch a vehicle door manual operation and a vehicle door automatic operation.
JP2001-277853A2, which corresponds to US2001/0033086A1, discloses an operating device for an automotive pivotal door. The operating device is provided with an electromagnetic clutch interposed between a driving power source and a vehicle door. The electromagnetic clutch, which is engaged and disengaged, establishes and interrupts a transmission path of a driving force from a driving power source to a vehicle door. Therefore, the operation device enables an automatic opening and closing operation of the vehicle door and also a manual opening and closing operation thereof, depending upon situations.
As described above, while a vehicle is provided with various types of functions and a vehicle quality itself has improved, a further requirement has been lead to a comfortable vehicle inside. In order to meet the requirement, noise occurrence due to vibration upon the vehicle driving is required to be reduced.
For example, in the operating device disclosed in JP2001-277853A2, a member such as a rubber-made sealing member is interposed between a vehicle body and a vehicle door, so as to prevent noise occurrence upon the vehicle driving. However, there may be a case that unpleasant noise may occur due to gear rotation via a ring. Further, while the vehicle has moved, a vehicle door operating device has been normally interrupts the clutch engagement. Therefore, a space between the driving power source and the vehicle door has been under a free condition, at which any restrain is applied. In this case, noise may occur due to a mechanical play between each gear in the operating device or a displacement therebetween. Although it is difficult to reduce these noises, the comfortable vehicle inside space may be interrupted due to the noises. In light of foregoing, these noises have been required to be reduced as much as possible so that sense of serenity in the vehicle can be improved.
A component such as a vibration-absorbing member can be attached at each component in a vehicle door operation-controlling device. Adding a new component to a conventional device, which has a limited inside space for attaching a component, is difficult. If a component is forced to be additionally provided at the device, the vehicle inside space may be constrained. Further, an additional component may lead to increase of a manufacturing cost. In light of foregoing, it may not be preferable.
A need exists for providing a vehicle door driving system capable of preventing noise occurrence due to vibration during vehicle driving without any additional component, thereby enabling to achieve a more comfortable vehicle inside.